John Vidal, the Guardian's environment editor, demonstrates either incompetence or dishonesty today with his comments concerning Exxon's greenhouse gas emissions. Here's what he has to say:

"But its greenhouse gas emissions in 2003 rose 2%, to 135m tonnes. To put that into perspective, the UK last year emitted some 150m tonnes. Exxon is now as great a carbon polluter as Indonesia, Malaysia, Thailand and the Philippines combined - that's about 350 million people."

However, a look at the accompanying graph indicates that the measurement is being made "on a CO2 equivalent basis."

The figures Mr. Vidal cites "to put that into perspective" are expressed in terms of carbon equivalent, not CO2 equivalent. As we learn from the US Environmental Protection Agency: "Carbon comprises 12/44 of the mass of carbon dioxide; thus to convert from CO2 equivalent to C equivalent, one multiplies by 12/44. [.273]"

So Guardian can't multiply. It makes sense, actually - they all went to Balliol,* after all.